1. Field of the Invention
The invention is directed to a method for high-resolution spectral analysis wherein signals are obtained in multiple channels. The invention is also directed to the employment of such a method for the detection of ventricular late potentials in multi-channel measuring methods in medical technology wherein signals derived from the heart are evaluated, such as magnetocardiography (MCG) or electrocardiography (ECG).
2. Description of the Prior Art
Methods for spectral analysis are required in order to find and in order to identify possibly attenuated, harmonic parts in signals with a large variety of origins.
Known methods for spectral analysis and their employment in the context of the identification of late potentials have been disclosed in the publications by D. E. Balderson, et al., "The Detection, Significance and Effect of Drugs upon Ventricular Late Potentials", Automedia, vol. 13, pp. 67-96, 1991 and E. J. Berbari et al., "An Introduction to High-Resolution ECG Recordings of Cardiac Late Potentials", Arch. Intern. med., vol. 148, pp. 1859-1863, August 1988. Further, the articles by S. M. Kay et al., "Spectrum Analysis--A Modern Perspective", Proceedings of the IEEE, Vol. 69, No. 11, November 1981, B. D. Rao et al., "Model based Processing of Signals: A State Space Approach", Proc. IEEE, vol. 80 pp. 283-309, Feb. 1992 and S. Haykin, Editor, "Nonlinear Methods of Spectral Analysis", Topics in Applied Physics, vol. 34, Springer-Verlag, 1979 provide a good survey of the known methods for spectral analysis.
These known methods have certain strengths and weaknesses. No known method, however, makes it possible to document ventricular late potentials in individual heartbeats employing multi-channel measured data.